The Relationship Between Morning Blood Pressure Surge And Ambulatory Arterial Stiffness Index And Blood Pressure Variability In Patients With Essential Hypertension

Objective: Hypertension has became one of the most common cardiovascular disease in the elderly with the aging society in China. Many hypertensive patients especially in the elderly display an exaggerated increase in blood pressure levels in the morning, referred to as the morning blood pressure surge(MBPS), a phenomenon that is known as an independent predictor of atherothrombotic cardiovascular events in current clinical studies. Morning blood pressure surge is defined as an excessive increase in blood pressure(BP) in the morning from the lowest systolic BP during sleep, even the highest level in a day. In this study, we evaluated the association between the morning blood pressure surge and ambulatory arterial stiffness index(AASI) derived from ambulatory blood pressure monitoring data analysis and blood pressure variability(BPV) in patients with essential hypertension.Methods: 50 patients with essential hypertension were selected in the department of cardiology in our hospital from January 2012 to September 2014, including 25 males, 25 females, age 34-82 years old, mean age 61.00±12.83 years old. All patients were diagnosed hypertension according to guidelines for prevention and treatment of hypertension in China(2010). All patients were taken blood tests, synchronous 24-hour ambulatory blood pressure(ABMP). According to the data derived from 24-hour ambulatory blood pressure, we calculate the morning blood pressure surge. The MBPS was calculated as mean systolic BP during the 2 hours after awaking minus the mean systolic BP during the 1 hour that included the lowest sleep BP. According to the MBPS, 50 patients were divided into two groups, elevated morning blood pressure surge group and non-elevated morning blood pressure surge group. The AASI value and indexes of blood pressure variability were recorded and compared between the two groups. Indexes of BPV include 24 hour systolic blood pressure standard deviation(24h SSD), daytime systolic blood pressure standard deviation(d SSD) and nocturnal systolic blood pressure standard deviation(n SSD).Results:1 Comparison of the two groups in general clinical data There were no significant differences in gender, age, body mass index(BMI), total cholesterol, triglyceride, fasting blood-glucose, low density lipoprotein and high density lipoprotein(P>0.05).2 AASI of two groups Morning blood pressure surge was more common in patients with essential hypertension. Compared with patients in the non-elevated morning blood pressure surge group, ambulatory arterial stiffness index was significantly higher in patients in the elevated morning blood pressure surge group(P<0.05).3 BPV of two groups Compared with patients in the non-elevated morning blood pressure surge group, 24 hour systolic blood pressure standard deviation, daytime systolic blood pressure standard deviation and nocturnal systolic blood pressure standard deviation were significantly higher in patients in the elevated morning blood pressure surge group(P<0.05).Conclusion:1 AASI was increased in essential hypertension patients with MBPS. There is a certain correlation between morning blood pressure surge and arterial stiffness, which is an important factor leading to a variety of target organ damage.2 BPV was significantly increased with increase of MBPS in essential hypertension patients. There is a correlation between morning blood pressure surge and blood pressure variability. It indicates that the possibility of getting target organ damage in the essential hypertension patients with MBPS tend to be greater. It also indicates that autonomic nerve function was damaged seriously. It means that sympathetic tone was increased.